Janet Kwasniak's blog on consciousness and the brain

The Edge Question 4

This post looks at the Edge Question responses that want to retire the genetic-environmental dichotomy. See (here) for the full responses to the question – What scientific idea needs to be retired?

It seems that ‘nature vs nurture’ is so out of favour that very few scientists refer to it in their work and when they do they are sharply criticized by other scientists. But it is something that the popular press and the general public will not drop. It is the cat that comes back. I believe the reason is that NvN has worked its way into how people view child rearing, policy decisions, politics and ideology. Each side of many arguments gather any scrap of evidence that they can to bolsters their side with either genetic or environmental causation of some effect in the population. So this fixation of NvN is no better for politics than it was for science. It is no wonder that four people chose this idea to retire.

Gopnik and Everett want to be rid of innateness. They give good and similar reasons based on the way that genetics and environment can not be separated. Some very good examples are included.

Gopnik gives three reasons to challenge the idea of innate traits. One development is the very important new work exploring what are called epigenetic accounts of development, and the new empirical evidence for those epigenetic processes. These studies show the many complex ways that gene expression, which is what ultimately leads to traits, is itself governed by the environment. Next: The increasingly influential Bayesian models of human learning, models that have come to dominate recent accounts of human cognition, also challenge the idea of innateness in a different way…the hypotheses and evidence are inextricably intertwined. Finally: The third development is increasing evidence for a new picture of the evolution of human cognition….The evolutionary theorist Eva Jablonka has described the evolution of human cognition as more like the evolution of a hand—a multipurpose flexible tool capable of performing unprecedented behaviors and solving unprecedented problems—than like the construction of a Swiss Army Knife…All three of these scientific developments suggest that almost everything we do is not just the result of the interaction of nature and nurture, it is both simultaneously.

Everett says the the terms innate and instinctive are not useful. (The newborns) cells have been thoroughly bathed in their environment before their parents mated—a bath whose properties are determined by their parents’ behavior, environment, and so on. The effects of the environment on development are so numerous, unstudied, and untested in this sense that we currently have no basis for distinguishing environment from innate predispositions or instincts. And further, many things that we believe to be instinctual can change radically when the environment changes radically, even aspects of the environment that we might not have thought relevant. In order to use the concept we would need to understand the genetic and evolutionary details of a trait. We are in no position at present to know the answers. And we will never be able to know some of the answers. Therefore, there simply is no utility to the terms instinct and innate. Let’s retire these terms so the real work can begin.

Pinker and Sapolsky go further and argue that the notions of gene-environment interaction, or that behavior = genes + environment are close to meaningless. They are discussing how this ‘interaction’ is not simple and the terms of the concept cannot be well defined.

Pinker starts by looking at the words in behavior = genes + environment and finding them confused.

Behavior: More than half a century after the cognitive revolution, people still ask whether a behavior is genetically or environmentally determined. Yet neither the genes nor the environment can control the muscles directly. The cause of behavior is the brain…

Genes:Molecular biologists have appropriated the term “gene” to refer to stretches of DNA that code for a protein. Unfortunately, this sense differs from the one used in population genetics, behavioral genetics, and evolutionary theory, namely any information carrier that is transmissible across generations and has sustained effects on the phenotype…. DNA is regulated by signals from the environment. How else could it be? The alternative is that every cell synthesizes every protein all the time! The epigenetics bubble inflated by the science media is based on a similar confusion.

Environment: This term for the inputs to an organism is also misleading. Of all the energy impinging on an organism, only a subset, processed and transformed in complex ways, has an effect on its subsequent information processing… The bad habit of assuming that anything not classically genetic must be “environmental” has blinkered behavioral geneticists (and those who interpret their findings) into the fool’s errand of looking for environmental effects for what may be randomness in developmental processes. Pinker describes the mess well – the mess of how the concept of environment is used and in the calculation of the so-called percentages of inherited and environmental influences on traits.

He also attacks the + sign. A final confusion in the equation is the seemingly sophisticated add-on of “gene-environment interactions.” This is also designed to confuse. Gene-environment interactions do not refer to the fact that the environment is necessary for genes to do their thing (which is true of all genes). It refers to a flipflop effect in which genes affect a person one way in one environment but another way in another environment, whereas an alternative genes has a different pattern.

Despite starting out writing about something else, he ends up talking about ‘gene-environment interaction’. He thinks that the phrase is OK, was good once, but now is misleading because it implies a single interaction. “My problem with the concept is with the particularist use of “a” gene-environment interaction, the notion that there can be one. This is because, at the most benign, this implies that there can be cases where there aren’t gene-environment interactions. Worse, that those cases are in the majority. Worst, the notion that lurking out there is something akin to a Platonic ideal as to every gene’s actions—that any given gene has an idealized effect, that it consistently “does” that, and that circumstances where that does not occur are rare and represent either pathological situations or inconsequential specialty acts. Thus, a particular gene may have a Platonically “normal” effect on intelligence unless, of course, the individual was protein malnourished as a fetus, had untreated phenylketonuria, or was raised as a wild child by meerkats…The problem with “a gene-environment interaction” is the same as asking what height has to do with the area of a rectangle, and being told that in this particular case, there is a height/length interaction.”